1. Field of the Invention
The present invention relates to an apparatus for handling materials, and more particularly to a mobile apparatus for loading and unloading open-top railcars.
2. Description of the Related Art
One method of loading and unloading open-top railcars has been to station large, fixed-base cranes or similar systems alongside railroad depots. However, loading and unloading must often be accomplished at a site remote from such a depot, such as during handling of cross-ties and track bed ballast for railroad construction or repair. Traditionally such unloading tasks have been accomplished via manual labor or by transporting large, highly specialized and expensive equipment to the job site. Manual labor has many disadvantages, including lack of efficiency and high expense. Alternatively, the costs of purchasing or renting expensive specialized equipment and the costs of transporting the equipment to each job site can also be prohibitive.
U.S. Pat. No. 4,175,902, titled APPARATUS FOR LOADING AND UNLOADING RAILROAD CARS, U.S. Pat. No. 4,190,394 titled METHOD FOR LOADING AND UNLOADING RAILROAD CARS, and U.S. Pat. No. 5,628,606, titled LOADING/UNLOADING APPARATUS FOR RAILROAD CARS, all to Stanley Herzog et al., are directed to an apparatus, a method, and an improved apparatus, respectively, for employing a specially adapted backhoe-like machine which has the capability to load or unload open-top railcars. In these patents, which are incorporated herein by reference, the specifically adapted machines, called xe2x80x9cCartoppers(copyright)xe2x80x9d backhoes can be easily transported to remote sites, where they are capable, with a trained operator and a front bucket-mounted winch, of loading themselves onto the top of the railcar. The machines include a front boom and a rear boom with respective buckets attached thereto. The machines can then be moved along the top of each railcar as material, such as railroad ties, track ballast, coal or other material is unloaded from, or loaded onto, the cars.
U.S. Pat. No. 4,175,902 shows an apparatus for loading and unloading railroad cars and includes supports attached to the front bucket, and to a chassis behind an operator""s cab. Center support feet added in U.S. Pat. No. 4,190,394 increase stability. U.S. Pat. No. 5,628,606 includes a pair of front support feet attached to a front bucket and a pair of swingable outrigger arms on the backhoe chassis behind the operator""s cab with the front and rear support feet resting on and overhanging the upper surfaces of the railcar sidewalls when the apparatus is positioned atop it. A center support assembly including a beam provides improved stability, and the center support can be readily extended or retracted depending on the task being performed (i.e. extended for tasks atop the railcar, retracted for ordinary tasks unrelated to loading/unloading a railcar).
As indicated, the prior designs are capable of self-mounting the railcars by coordinated use of the front and rear booms. Once atop the railcars, movement along upper surfaces of sides of the cars is accomplished by alternately folding the rear boom and engaging the railcar""s bottom surface and then unfolding the same to slide the front and rear supportive feet along the upper surfaces. The apparatus can also be moved in the opposite direction atop the cars by pulling with the rear boom. Alternatively, the apparatus can be moved by a winch attached to the front bucket.
While the prior designs have proven effective, a need remains for a railcar loading/unloading apparatus, such as a conventional trackhoe, that can be easily positioned and moved atop a railcar or system of railcars to load or unload the railcar""s contents.
The present invention is directed to an apparatus for loading and unloading""railcars. Although the apparatus as described includes a trackhoe type machine, other machines such as a bulldozer, backhoe, or other mobile apparatus also could be used. The apparatus allows for relatively easy movement atop the railcar, and a relatively large bucket to handle greater loads. The apparatus includes an upper body and a lower body. The upper body includes an articulated boom with a material handling bucket attached thereto. The lower body includes a supportive chassis and a pair of track subassemblies for movement.
A plurality of support subassemblies are attached to the chassis and provide support and stability when the apparatus is positioned atop the railcar with the support subassemblies in positions to engage upper and outer surfaces of the railcar""s sidewalls. The support subassemblies are readily removable.
The apparatus can mount a railcar via a ramp, or, alternatively, by climbing an end thereof. Once atop the railcar, movement is accomplished either directly by rotation of the track subassemblies, or, alternatively, by using the boom and bucket to push or pull the apparatus along the railcar.
In an alternative version, rollers are attached to the support subassemblies to afford easier movement by reducing travel friction when the support assemblies engage upper surfaces of the railcar""s sidewalls.
The principle objects and advantages of the present invention include: providing an improved railcar loader/unloader apparatus; providing such an apparatus that can be readily positioned atop an open-top railcar; providing such an apparatus that is able to negotiate different materials once atop the railcar; providing such an apparatus with improved stability, versatility and load carrying capabilities; providing such an apparatus with improved mobility; providing such an apparatus with a plurality of support subassemblies; providing such support subassemblies which are readily removable; providing such an apparatus with rollers attached to the support subassemblies to reduce travel friction; and to provide such an apparatus which is safe, durable and reliable, and which is particularly well adapted for its intended purposes.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.